Putin to chair meeting on nuclear deterrence, Kremlin says

President Vladimir Putin will chair a meeting of Russia's Security Council on Wednesday on nuclear deterrence, the Kremlin said, as Moscow weighs how to respond to Ukraine's requests to Western countries to allow it to strike deep into Russia with long-range Western missiles.

The 2-1/2-year-old Ukraine war has caused the worst confrontation between Russia and the West since the 1962 Cuban Missile Crisis - which is considered to be the time when the two Cold War superpowers came closest to intentional nuclear war.

Kremlin spokesman Dmitry Peskov described Wednesday's meeting as an important event.

"There will be a speech by the president. The rest, for obvious reasons, will be marked 'top secret'," Peskov told reporters.

Russia has said it is in the process of revising its nuclear doctrine which sets out the circumstances in which it might resort to the use of nuclear weapons.

Russia will not test a nuclear weapon as long as the United States refrains from testing, Putin's point man for arms control said on Monday after speculation that the Kremlin might abandon its post-Soviet nuclear test moratorium.